The Scottish Naturalist. 55 



The bird best known in connection with the Bass is the 

 Gannet or Solan Goose (Sula alba). The number of 

 these birds which yearly frequent the rock has been estimated 

 at 20,000. They remain only during the breeding season, and 

 leave as soon as the young ones are able to fly, which is not 

 till the end of September or October, — often, however, return- 

 ing to inspect their home during winter. The young of the 

 Gannet, when first hatched, are quite black and are more like 

 frogs than birds. In the course of a week, however; they are 

 covered with a thick white down. When they get their 

 feathers they again change their colour, and for the first year 

 are of a dark grey, with light spots. The second year the grey 

 is mixed with white, which increases yearly until they reach 

 their mature plumage, at the fourth year. The nests, which 

 are built on ledges on the steepest sides of the rock, are formed 

 of seaweed and grass, and so thickly are they placed, that, when 

 the birds are sitting, the rock at a little distance looks quite 

 white. 



The Herring Gull (Lams argejitatus) breeds in limited 

 numbers on the Bass. When visiting the rock in August last 

 (r-872 ■, we observed 8 or 10 old birds seated on a point of 

 rock above the landing place. By that time the young had 

 all left, and the return of those we saw was looked upon with 

 satisfaction by the boatmen who accompanied us, as a sign that 

 herring were plentiful in the Firth. 



The Kittiewake (Larus Iridactylus ) is very common ; 

 its peculiar cry mingling not unpleasantly with the deeper 

 note of the Gannets as they fly overhead, when frightened from 

 their nests at the approach of an intruder. 



The Common Gull (Larus canus). Common, not only on 

 the Bass, but on the east coast in general this bird is found in 

 much greater numbers than on the west. 



# 



The Great Bla.ck- Backed Gull (Larus marinus) fre- 

 quents the rock in limited numbers, but its smaller connection, 



The Lesser Black-Backed Gull (Larus fuscus) is far 

 from uncommon, attracted no doubt by the numbers of Razor- 

 bill and Gulliemot eggs, for which it has a' decided liking. 



The Common Gulliemot ( Uria troile) is very abundant and 

 equals, if not excels, the numbers even of the Solan Geese. 



